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61.
采用沉淀-双氧水氧化法,对制革铬鞣废水中铬(Ⅲ)的治理和回收利用进行了研究.该法对铬(Ⅲ)的回收率可达92%,处理后废水澄清,无色,无味,稳定,pH值8~8.5. 相似文献
62.
H2O2与UV/TiO2协同体系光催化降解酸性品红的研究 总被引:3,自引:0,他引:3
采用高压汞灯为光源,考察了H2O2与UV/TiO2协同体系对酸性品红的降解效果。结果表明:H2O2提高了UV/TiO2光催化降解酸性品红的速率。同时,研究了影响纳米TiO2光催化降解酸性品红的主要影响因素。实验结果表明:初始PH值等于7时,光催化效率最佳;随着初始浓度的增加光催化降解效率降低;TiO2的最佳用量为0.2g/L。 相似文献
63.
通过对有丝分裂中期及减数分裂终变期染色体数目统计,形态、行为的观察,发现莱麦草染色体呈现广泛的变异:有丝分裂中期株内染色体数目在2n=11──56内变化,含有本物种染色体数目2n=28的细胞仅占统计数的27.8%。减数分裂终变期出现36%具非整倍性的花粉母细胞,染色体数除数目变异外还有结构变异如Robertson易位等。本文对该种进行了染色体组分析,确认其为同源四倍体。同时对该物种株内产生混倍性的原因,在物种进化上的意义进行了探讨。 相似文献
64.
65.
论张学良在西安事变和平解决中的地位和作用 总被引:1,自引:0,他引:1
范丽红 《东北大学学报(社会科学版)》2007,9(3):258-262
西安事变的和平解决是促成蒋介石接受张、杨及中共抗日思想的关键.西安事变能够和平解决,真正起决定作用的是事变的主角张学良.在整个西安事变的发展过程中,张学良不仅是和平解决事变的倡导者,还是促进西安事变和平解决的实施者,张学良作为西安事变和平解决的主体地位以及发挥出的决定性作用,是应该给予充分肯定的. 相似文献
66.
唯美主义与同性恋视野中的王尔德 总被引:1,自引:0,他引:1
何昌邑 《云南民族大学学报(哲学社会科学版)》2007,24(6):128-132
国内对奥斯卡.王尔德的研究集中在他的唯美主义观和戏剧方面,而对其蕴涵的同性恋倾向和寓意往往是批评性地一笔带过。在王尔德的《W.H.先生的肖像》和《道连.格雷的画像》中,可以看出:前者是王尔德对同性恋历史的追溯和对莎翁十四行诗中隐含同性恋内涵的证实;后者表征了王尔德对同性恋的困惑和探索以及在同性恋视野中王尔德的人生底蕴和美学观。 相似文献
67.
Oeindrila Dube Omar García‐Ponce Kevin Thom 《Journal of the European Economic Association》2016,14(5):1181-1224
Understanding how economic incentives affect illegal drug production is essential for crafting policies in response to the international drug trade. Policymakers typically face a choice between two strategies: targeting criminal groups via law enforcement, and offering producers incentives to engage in alternate activities. Yet, little is known about how the returns to alternate legal activities affect drug supply. We contribute to this literature by examining how shocks to legal commodity prices affect the drug trade in Mexico. Our analysis exploits exogenous movements in the Mexican maize price stemming from weather conditions in US maize‐growing regions, as well as exports of other major maize producers. Using data on over 2200 municipios spanning 1990–2010, we show that lower prices differentially increased the cultivation of both marijuana and opium poppies in municipios more climatically suited to growing maize. We also find impacts on downstream drug‐trade outcomes, including drug cartel operations and killings perpetrated by these groups. Our findings demonstrate that maize price changes contributed to the burgeoning drug trade in Mexico, and point to the violent consequences of an expanding drug sector. 相似文献
68.
Europe's debt crisis resembles historical episodes of outright default on domestic public debt about which little research exists. This paper proposes a theory of domestic sovereign default based on distributional incentives affecting the welfare of risk‐averse debt and nondebtholders. A utilitarian government cannot sustain debt if default is costless. If default is costly, debt with default risk is sustainable, and debt falls as the concentration of debt ownership rises. A government favoring bond holders can also sustain debt, with debt rising as ownership becomes more concentrated. These results are robust to adding foreign investors, redistributive taxes, or a second asset. 相似文献
69.
Brd Harstad 《Journal of the European Economic Association》2016,14(3):719-752
This paper analyzes a framework in which countries over time pollute and invest in green technologies. Without a climate treaty, the countries pollute too much and invest too little, particularly if intellectual property rights are weak. Nevertheless, short‐term agreements on emission levels then reduce every country's payoff, since countries invest less when they anticipate future negotiations. If intellectual property rights are weak, the agreement should be tougher and more long‐term. Conversely, if the climate agreement happens to be short‐term or absent, intellectual property rights should be strengthened or technological licensing subsidized. 相似文献
70.
This study introduces an individual’s perception of their entrepreneurial potential in terms of their age (age-based self-image) to complement chronological age as a predictor of entrepreneurial behaviour. The principal hypothesis is that a positive age-based self-image enhances the likelihood of individuals turning their intention to start a business into actual behaviour. The empirical analysis based on data collected on the general adult population of Finland in 2011 and 2012 (n = 672) supports this hypothesis. The analysis further shows that this positive effect is independent of the individual’s chronological age, and it is thus applicable to both age groups that are under-represented in entrepreneurship: ‘youngsters’ and ‘seniors’. Promoting the development of a positive age-based self-image is a prospective policy option for fostering entrepreneurship among younger and older age groups. More in-depth research, especially concerning the antecedents of positive age-based self-image, is required for the effectiveness of such policy interventions. 相似文献